When Macy Halford started a job at The New Yorker in late 2004, headlines told her that a book that had shaped her Southern Baptist faith had also shaped the faith of George W. Bush. The book in question, a collection of devotional readings titled “My Utmost for His Highest,” had been beloved by evangelicals since its publication in 1927. Halford, who, like the president, was a Christian raised in Texas, was unsettled to think that her faith now might mark her as someone who stood by this president’s politics. Whose book was this, then? His or hers?

In order to answer that question, Halford set out to discover everything she could about Oswald Chambers, the Scottish minister who wrote the book. “My Utmost: A Devotional Memoir” tells the story of Chambers’s intellectual and spiritual formation as it follows Halford’s drift from the Dallas girl who had loved lines like “Think of the healing and far-flung rivers nursing themselves in our souls!” to a believing yet anchorless adult. “Now, when I thought of God,” Halford writes of her New York days, “the noise came flooding immediately in, the voices of a thousand pundits and politicians and preachers, the flickering images of a dozen holy wars, all lit by the eternal light of the screen.”

Halford’s book is billed as a memoir, but it’s really an ardently told, diligently researched intellectual biography of Chambers. Perhaps the most important thing to know about him is that the title of his book didn’t come from Scripture but from the writings of a Victorian symbolist painter. Before finally giving himself over to the ministry, Chambers, born in 1874, was an art student who admired the writings of John Ruskin and dreamed of saving souls through his painting. Halford is an expert, assured surveyor of all the rivers that nursed Chambers’s soul — whether she’s parsing minuscule differences between various evangelical doctrines, or suggesting a line from Scottish folk beliefs to the Victorian fantasy writer George MacDonald.

“My Utmost” will be enjoyed and admired primarily by those who feel, as Halford does, “a complicated nostalgia” for the evangelical faith they were raised in — those who can’t and won’t defend all the old doctrines but find that religion still pulls at them when they come up against, as she puts it, “the fact that there are limits on what we know and what we can know; the fact that we all must learn to live with mystery, however clever we are, however much of it we dispel.” And by those who struggle, or struggled, as Halford did, to reconcile the person who wants to believe with the person who wants to think. But those readers may also long for just a little more confession. What was Barnard College like for an obedient girl from Dallas? What exactly did the man she fell in love with in Paris — referred to here only as “the mountaineer” — make of her faith? Readers who, like Halford, chose to worship books instead of just one Book, who chose pluralism over narrow-minded huddles, can sometimes ache for family stories, as it were, from siblings who know what it was like to wish for escape from those warm sanctuaries while worrying that the larger world might prove too cold.

But there’s a bigger gift here, if we’re talking about family stories. Halford acknowledges that growing up evangelical can make one feel that one has inherited a traditionless tradition. With “My Utmost” she reminds those of us who might have once dismissed Chambers as just another bewhiskered eminence that in this traditionless tradition there lives a man who read Balzac, Emerson, Nietzsche, Wilde, Dickens, Darwin and others with ferocity and humility, confronting dissent rather than hiding from it. “I begin to notice with astonishment that I do not read in order to notice what I disagree with,” Chambers wrote in the last year of his life. “The author’s conclusions are of very little moment to me, what is of moment is a living mind competently expressed, that to me is a deep joy.” Such generosity of mind is just as worthy of celebration as unshakable faith.

Carlene Bauer is the author of the novel “Frances and Bernard” and the memoir “Not That Kind of Girl.”